We will determine if the release of E. coli DNA from the cell membranes by S1 endonuclease reflects sequence specificity in the attachment points. This will be done by a study of restriction enzyme fragments and hybridization with DNA of phage Mu or lambda integrated at different sites. We will attempt to study the apparent heterogeneity of the E. coli cell membrane by kinetic studies of the formation of protein-lipid complexes, translocation of lipids from the inner to the outer membrane, and turnover of phospholipids.